Transient temperature monitoring and safe cutting speed exploration in diamond turning of PBX surrogates

Abstract

In diamond turning of polymer bonded explosives (PBXs), a transient temperature monitoring tool is crucial for the processing safety issues. Three design principles are proposed in this work to fulfill the accurate prediction of the temperature distribution on tool cutting edge by using gradient calibration method and heat transfer simulation. Subsequently, the detailed design, microfabrication, and self-calibration test are successfully performed to establish the temperature measuring tool based on a natural diamond cutting tool. A theoretical model is further established to predict the transient temperature of the tool tip in the limit turning experiment and explore the safe cutting factors of typical PBXs. The results show that (1) the unsteady heat transfer model can better describe the self-calibration process of the tool, and it can accurately predict the transient temperature on the tool tip using the error distribution law; (2) finite element method can not only obtain the global temperature distribution field but also analyze the influences of tool structure, material selection, and thermal boundary conditions on prediction errors; and (3) cutting speed, tool tip wear, dry cutting are the key factors that affect the cutting safety of PBXs, and the maximum safe cutting speed vmax ≈ 33.5 m/s.